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I. S'QDAVIS. SPRING HINGE.

(No Model') Patented Mar. 211,' 1882.

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UNITED STATES PATENT OFFICE.

, lIRA s. DAvIs,I OFDETROIT, MICHIGAN, AssIGNon To THE EDWARDS i MANUFACTURING ooIi'IPANY, 0F SAME PLACE` SPRING-Hmm.

SPECIFICATION forming part of Letters Patent No. 255,257, dated March 21, 1882.

- Application tiled December 5, 1881. (No model.) i

tated by turning` one portion of the pintle to any desired position.

Figures 1 and 2 are elevations of a springhinge containing my invention. Fig. 3 is a detached view of the pintle taken apart. Fig. 4 is a detached View of the pintle put together, with a section of the upper lug, drum, and loose collar thereon.

Y'A and B are the leaves of a hinge, having lugs C D E F thereon. On the under side ot' lug E is cast or formed one or more ratchetteeth.

-Kis a regulating-drum, on one side of which are cast ratchet-teeth, adapted to interlock with the ratchet-teeth on lug E, the other sidey O is a coiled metal spring, one end of which is fastened to the regulating-drum K, the other end resting lin a loose collar, L, and being turned out so as to bear againstleaf A. This spring 0 may belong enough to nearly or quite lill the space between drum K, when in the position shown in Figs. l and 2, and collar L, without being compressed longitudinally, but need not be long enough to lkeep the ratchetteeth on drum K and lug E locked together when the hinge' is in actual use.

G H is a pintle, which runs through the lugs on leaves A and B, holding said leaves together. This pintle is made in two pieces, the piece H being long enough to extend nearly to the upper side of drum K when in the position shown in Figs. land 2, and the piece G being long enough to extend to the other side of drum K, and having at its end a screwthreaded rod, R. A longitudinal hole is tapped in the end of piece H, and a screw-thread cut therein, so that pieces G H can be screwed together. The end of piece H is beveled so as to form a square, which will fit into a square hole cut through the center of drum K, and piece G is too large to pass through the hole in drum K.

When spring O is too short to till the `space between drum K and collar L, I use a small spiral spring, T, Fig. l, lying between the shoulder on piece Gr and the upper surface ot' lug G, said lug being extended a short distance above leaf A, and being cored out sufficiently to receive and conceal spring T.

L is a loose collar on pintle G H, to prevent wear on the end of spring 0.

The principal defect in spring-hinges of the class in which the tension of the spring is regulated by rotating a drum fastened to one end of the spring and having ratchet-teeth thereon is the difcult-y of releasing the tension of the spring. Another difculty consists in the liability of the locking mechanism to open when it is held locked sim ply by the longitudinal elasticity of the spring which operates the hinge. These are entirely overcome by my invention.

When it is desired to increase the tension of the spring O the part G of pintle G H is unscrewed a little more than the depth ot' the ratchet-teeth on drum K. The ratchet-teeth on drum K and lug E are kept locked by spring T when spring 0 is too short to do so,and by spring O when long enough. Drum K is then rotated by turning thepart H ofypintle G H, which may be done by a wire or rod inserted in the hole through said pintle. (Shownin Fig. 3.) As soon as spring 0 has the desired tension the parts G H of the pinlle are screwed together, thereby drawing drum K against lug E and holding the ratchet-teeth on said drurn and lug firmly nterlocked. To release the tension of spring 0 it is only necessary to nnscrew the two parts of the pintle as before, and then press upon the portion Guntil drum K is pushed so far away from lug E as to unlock the ratchet-teeth on said drum and lug, when the elasticity of spring O will rotate drum K until the springis relieved ofthe strain upon it. 1

I do not wish to confine myselfto the precise manner ot' making connection between drum K and part H of pintle G H shown in the IOO drawings, as it is only necessary to so connect on, with the pintle G H, made in two parts f them that drum K cannot turn or slide on pinadapted to screw together, the upper end of tle G H. part H being made to tinto a hole in the cen- When the small spring T is not used lng C ter of drum K, whereby said pintle andl drum 5 may be made in the ordinary manner, flush cannotrotateindependently ofeachothelysnb- 15 with the upper edge of leaf A. stantialiy as shown and described. l

What 1 claim as my invention, and desire IRA S. DAVIS. to secure by Letters Patent, is- Witnesses:

ln a, spring-hinge, the combination of the GEO. H. CARLISLE, 1o regulatingdrum K,havingratchetteeth there- CHARLES B. LoTHRoP. 

